Prodrugs of CL316243: a selective beta3-adrenergic receptor agonist for treating obesity and diabetes

CL316243 is a highly selective and potent beta3-adrenergic receptor agonist, and has been shown in rodent models to be an effective agent for treating obesity and Type II diabetes. To improve the oral absorption and pharmacokinetic profiles of CL316243, a number of prodrugs have been synthesized and evaluated. Several ester-type prodrugs show significant improvements in oral bioavailability in both rodent and primate models.

Differential regulation of protooncogene c-myc expression in rat ventral prostate after castration

To evaluate the possibility that the protooncogene c-myc plays a role in ventral prostate, the effects of castration have been investigated at a beginning of a period by Northern blot hybridization and the levels of c-myc mRNA were also compared with mRNA of androgen-regulated genes, C1 and TRPM-2. Levels of c-myc mRNA in ventral prostate increased with maximal stimulation reached at 6 hours (early induction) and 48 hours (late induction) after castration, respectively. The level of C1 mRNA did not change and TRPM-2 was not detected at early induction of c-myc mRNA after castration. The level of early induction of c-myc mRNA after castration was increased in ventral prostate treated with cycloheximide, but it was almost reduced by actinomycin-D pretreatment. Administration of androgen at the time of castration prevented early induction of c-myc mRNA. These results suggest that protooncogene c-myc is differentially regulated in ventral prostate after castration.

Regulation of Na,K-ATPase activity in renal basolateral membrane of 1-clip-1-kidney hypertensive rat

The changes of Na,K-ATPase activity and its regulation have been investigated in the renal cortex of 1-clip-1-kidney hypertensive rat. Ouabain-sensitive Na,K-ATPase activity (Emax) and [3H]ouabain-binding site (Bmax) in the hypertensive rat were slightly increased than those in the control. The levels of Na,K-ATPase alpha 1- and beta 1-subunit mRNA of the renal cortex in hypertensive rat were more increased than those in the control. Their increases were repressed by actinomycin-D, but not altered or more increased by cycloheximide. These results suggest that the increase of Na,K-ATPase activities and ouabain binding sites in 1-clip-1-kidney hypertensive rat may be correlated with the increases of gene expression in transcription level and/or of mRNA stability of Na,K-ATPase.

Crystal structure of monoclonal 6B5 Fab complexed with phencyclidine

The crystal structure of monoclonal antibody (mAb) 6B5 Fab fragment complexed with 1-(1-phenylcyclohexyl)piperidine (PCP or phencyclidine) was determined at 2.2-A resolution. 6B5 was originally produced from a mouse immunized with a phencyclidine analogue hapten 5-[N-(1'phenylcyclohexyl)amino]pentanoic acid conjugated to bovine serum albumin. This mAb was selected for further study because of its high affinity (Kd = 2 x 10(-9) M/liter) for PCP and usefulness in reversing PCP-induced central nervous system toxicity in laboratory animals. The dominant feature of the 6B5 Fab.PCP complex is the deep binding site and hydrophobic nature of the interaction. The ligand binding pocket of 6B5 Fab has numerous aromatic side chains, as compared with other known Fab structures. The most notable feature of the binding site is a Trp at position 97H (H-chain), and the side chain of this residue appears to act as a hydrophobic umbrella on the ligand in the antigen binding pocket. There are only two other known Fabs found with a Trp at the 97H position in complementarity determining region (CDR) H3, but they do not play a major role in the interaction with their respective antigens; in both Fab TE33 and R6.5 the Trp 97H side chain is positioned away from the bound antigen. Comparison of the CDR residues of 6B5 with other Fab structures with similar CDR sizes and amino acid compositions reveals a number of important patterns of residue substitutions that appear to be critical for specific PCP ligand interactions.

Reduced level of ATF is correlated with transcriptional repression of DNA topoisomerase II alpha gene during TPA-induced differentiation of HL-60 cells

DNA topoisomerase II is a marker for the proliferation state of mammalian cells in culture, and the protein levels are markedly higher in exponentially growing cells than quiescent cells and can be downregulated by growth of the cells at high density and serum starvation. Correlation between ATF and TPA-repressed DNA topoisomerase II alpha (Topo II alpha) mRNA has been investigated during TPA-induced differentiation of HL-60 cells. Topo II alpha mRNA and unknotting activity were reduced at 24 hours in TPA-treated HL-60 cells. The level of Topo II alpha mRNA and the activity were gradually decreased in proportion to the concentration of TPA. Two DNA-protein complexes were formed by DNA mobility shift assay when ATF-binding site was incubated with nuclear extract prepared from TPA-free HL-60 cells, and the amount of ATF was vanished after TPA treatment. TPA-repressed Topo II alpha mRNA and ATF levels were partially restored after pretreatment of staurosporin. These results suggest that the reduced level of ATF may be important to the transcriptional repression of Topo II alpha gene during TPA-induced differentiation in HL-60 cells and related to protein kinase C signal pathway.

Locations of bromide ions in tetragonal lysozyme crystals

Anions have been shown to play a dominant role in the crystallization of chicken egg-white lysozyme from salt solutions. Previous studies employing X-ray crystallography have found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystals grown in bromide and chloride solutions. Five possible anion-binding sites were found in this manner. Some of these sites were in pockets containing basic residues while others were near neutral, but polar, residues. The sole chloride ion binding site found in previous studies was confirmed, while four further sites were found which corresponded to the four binding sites found for nitrate ions in monoclinic crystals. The study suggests that most of the anion-binding sites in lysozyme remain unchanged even when different anions and different crystal forms of lysozyme are employed.

Human eosinophil-lymphocyte interactions

While the eosinophil's effector functions clearly can contribute to the pathogenesis of allergic diseases, the evolutionary benefit to having eosinophils as a distinct class of leukocyte is not clear, especially if one must reconsider the nominally beneficial role of eosinophils in parasite host defense, Eosinophils are equipped to respond to lymphocytes and their cytokines (and not solely the eosinophil growth factor cytokines), but the functional consequences of such eosinophil responses need to be defined. Conversely, eosinophils, as antigen-presenting cells (APCs) or sources of lymphocyte-active cytokines, may stimulate and affect lymphocyte functioning. Eosinophils share with CD4+ lymphocytes expression of a number of receptors, including CD4 and IL-2R, and specific alpha-4 integrins that may help in their common recruitment and activation. Further, elucidation of the interactions between lymphocytes and eosinophils will contribute to a broader understanding of the functioning of eosinophils in "normal" ongoing immune responses and in allergic disorders.

Aldosterone stimulates Na,K-ATPase activity in basolateral membrane of rat kidney

The changes of Na,K-ATPase activity and its regulation have been investigated in the renal cortex and its basolateral membrane of aldosterone-induced hypertensive rat. Ouabain-sensitive Na,K-ATPase activity and [3H]ouabain-binding site (Bmax) in the hypertensive rat were significantly increased than those in the control. The levels of Na,K-ATPase alpha 1- and beta 1-subunit mRNA of the renal cortex in hypertensive rat were more increased than those in the control, and their increases were repressed by actinomycin-D. These results suggest that the increase of Na,K-ATPase activities and ouabain binding sites in aldosterone-induced hypertensive rat may be correlated with transcriptional regulation of Na,K-ATPase gene expression.

TATA element-binding protein is important to epidermal growth factor-dependent induction of H2B histone gene expression in primary hepatocytes from rat

Epidermal growth factor (EGF) is a potent mitogen for rat hepatocytes and mammalian histone synthesis is functionally and temporally coupled to DNA replication. To gain an insight on the role of EGF in the regulation of H2B histone gene expression in primary hepatocyte cultures, the binding patterns of nuclear proteins to various elements in the H2B histone gene upstream region have been investigated. EGF induced H2B histone mRNA with maximal stimulation reached at 36 hours. The induction of H2B histone mRNA was dependent on the concentration of EGF and almost reduced by actinomycin-D pretreatment. In DNase I footprinting analysis, one nuclear factor (TATA element-binding protein, TBP) bound at -20 bp (TATA element) in either the absence or presence of EGF. One DNA-protein complex was formed by DNA mobility shift assay when TATA element was incubated with nuclear extract prepared from EGF-free hepatocytes, and the amount of TBP was increased after EGF treatment. These results suggest that TBP may be correlated with transcriptional regulation of H2B histone gene by EGF in primary hepatocytes.

Catastrophic antiphospholipid syndrome. Clinical and laboratory features of 50 patients

We analyzed the clinical and laboratory characteristics of 50 patients with catastrophic antiphospholipid syndrome (APS) (5 from our clinics and 45 from a MEDLINE computer-assisted review of the literature from 1992 through 1996). Thirty-three (66%) patients were female and 17 (34%) were male. Twenty-eight (56%) patients had primary APS, 15 (30%) had defined systemic lupus erythematosus (SLE), 6 (12%) had "lupus-like" syndrome, and 1 (2%) had rheumatoid arthritis. Mean age of patients in this series was 38 +/- 14 years (range, 11-74 yr). Three (6%) patients developed the clinical picture of catastrophic APS under the age of 15 years, and 11 (22%) were 50 years old or more. In 11 (22%) patients, precipitating factors contributed to the development of catastrophic APS (infections in 3, drugs in 3, minor surgical procedures in 3, anticoagulation withdrawal in 2, and hysterectomy in 1). The presentation of the acute multi-organ failure was usually complex, involving multiple organs simultaneously or in a very short period of time. The majority of patients manifested microangiopathy--that is, occlusive vascular disease affecting predominantly small vessels of organs, particularly kidney, lungs, brain, heart, and liver--with a minority of patients experiencing only large vessel occlusions. Thrombocytopenia was reported in 34 (68%) patients, hemolytic anemia in 13 (26%), disseminated intravascular coagulation in 14 (28%), and schistocytes in 7 (14%). The following antibodies were detected: lupus anticoagulant (94%), anticardiolipin antibodies (94%), anti-dsDNA (87% of patients with SLE), antinuclear antibodies (58%), anti-Ro/SS-A (8%), anti-RNP (8%), and anti-La/SS-B (2%). Anticoagulation was used in 70% of the patients, steroids in 70%, plasmapheresis in 40%, cyclophosphamide in 34%, intravenous gammaglobulins in 16%, and splenectomy in 4%. Most patients, however, received a combination of nonsurgical therapies. Death occurred in 25 of the 50 (50%) patients. In most, cardiac problems seemed to be the major cause of death. In several of these, respiratory failure was also present, usually due to acute respiratory distress syndrome and diffuse alveolar hemorrhage. Among the 20 patients who received the combination of anticoagulation, steroids, and plasmapheresis or intravenous gammaglobulins, recovery occurred in 14 (70%) patients. The use of ancrod and defibrotide appeared to be effective in the 2 respective patients in whom they were used.

On defining the rules for interactions between the T cell receptor and its ligand: a critical role for a specific amino acid residue of the T cell receptor beta chain

The specificity of T cell-mediated immune responses is primarily determined by the interaction between the T cell receptor (TCR) and the antigenic peptide presented by the major histocompatibility complex (MHC) molecules. To refine our understanding of interactions between the TCR and the antigenic peptide of vesicular stomatitis virus (VSV) presented by the class I MHC molecule H-2Kb, we constructed a TCR alpha chain transgenic mouse in a TCR alpha-deficient background to define specific structural features in the TCR beta chain that are important for the recognition of the VSV/H-2Kb complex. We found that for a given peptide, a peptide-specific, highly conserved amino acid could always be identified at position 98 of the complementarity-determining region 3 (CDR3) loop of TCR beta chains. Further, we demonstrated that substitutions at position 6, but not position 1, of the VSV peptide induced compensatory changes in the TCR in both the amino acid residue at position 98 and the length of the CDR3beta loop. We conclude that the amino acid residue at position 98 of the CDR3beta loop is a key residue that plays a critical role in determining the specificity of TCR-VSV/H-2Kb interactions and that a specific length of the CDR3beta loop is required to facilitate such interactions. Further, these findings suggest that the alpha and beta chains of TCRs interact with amino acid residue(s) toward the N and C termini of the VSV peptide, respectively, providing functional evidence for the orientation of a TCR with its peptide/MHC ligand as observed in the crystal structures of TCR/peptide/MHC complexes.

Molecular characterisation of tumour infiltrating lymphocytes in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is often associated with a lymphocytic infiltrate that is believed to represent an in vivo immune reaction to the tumour cells. In this study, the tumour-infiltrating lymphocytes (TIL) associated with primary OSCC were characterised molecularly in six newly-diagnosed patients to determine the nature of the immune response to the primary tumour. The primary tumours in three of the six patients were associated with a moderate to dense CD8+ T cell infiltrate whilst the cellular infiltrate in the other primary tumours was sparse. The CD3+ T cells were also HLA-DR+. In all cases, there were few CD56+ cells, suggesting that TIL were predominantly T cells bearing the alpha/beta T cell receptors (TCR). The TCR Vbeta repertoire of TIL in these six cases was analysed. TCR Vbeta gene usage by TIL was heterogeneous. A restricted usage of TCR Vbeta genes by TIL was evident in two tumours associated with a dense CD3+ T cell infiltrate. In one of these, there was histological evidence of tumour cell destruction by TIL. Further analysis of the predominant TCR Vbeta gene family used by TIL in this individual showed a unique in-frame nucleotide sequence in 100% of the transcripts. This recurrent transcript was not detected in the peripheral blood of this patient, indicating a local T cell clonal expansion in the vicinity of the tumour. Overall, these results suggest that activation and clonal expansion of T cells occurs and may play a role in local tumour destruction in OSCC.

Atomic structure of an alphabeta T cell receptor (TCR) heterodimer in complex with an anti-TCR fab fragment derived from a mitogenic antibody

Each T cell receptor (TCR) recognizes a peptide antigen bound to a major histocompatibility complex (MHC) molecule via a clonotypic alphabeta heterodimeric structure (Ti) non-covalently associated with the monomorphic CD3 signaling components. A crystal structure of an alphabeta TCR-anti-TCR Fab complex shows an Fab fragment derived from the H57 monoclonal antibody (mAb), interacting with the elongated FG loop of the Cbeta domain, situated beneath the Vbeta domain. This loop, along with the partially exposed ABED beta sheet of Cbeta, and glycans attached to both Cbeta and Calpha domains, forms a cavity of sufficient size to accommodate a single non-glycosylated Ig domain such as the CD3epsilon ectodomain. That this asymmetrically localized site is embedded within the rigid constant domain module has implications for the mechanism of signal transduction in both TCR and pre-TCR complexes. Furthermore, quaternary structures of TCRs vary significantly even when they bind the same MHC molecule, as manifested by a unique twisting of the V module relative to the C module.

The use of augmented-pressure colostography in imperforate anus

Colostomy is recommended in most newborns with imperforate anus (IA), except those with low-type anorectal malformations (ARM). Accurate demonstration of the anatomy of any associated fistula between the rectum and the urogenital tract is essential for optimal surgical management. Augmented-pressure distal colostography is recommended to fulfill this requirement prior to definitive surgical repair of IA. We examined 12 cases of high or intermediate-type ARM using this technique, which clearly demonstrated the distal perineal anatomy. All were confirmed at posterior sagittal anorectoplasty.

The pattern of cytokine mRNA expression in ovarian endometriomata

Intraovarian cytokines play a pivotal role in the normal growth and development of the ovarian follicle. The purpose of this study was to investigate the pattern of cytokine mRNA expression in ovarian endometriomata. A total of 10 patients with histologically confirmed endometriomata undergoing surgery formed the study group while nine patients undergoing sterilization with no evidence of a cyst in the ovary formed the control group. Biopsies of the ovary were obtained at surgery and stored in liquid nitrogen until processed by reverse transcription-polymerase chain reaction amplification to identify the presence of mRNA for interleukin (IL)-1, IL-2, IL-4, IL-6, IL-8, IL-10, IL-13, tumour necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma). IL-6 and IL-10 mRNA were expressed by nine and seven patients respectively in the endometriosis group compared with three and one patients in the control group; this difference was significant (P < 0.05). IL-1 alpha mRNA was expressed by seven of 10 patients with endometriosis but by only one of the control group; this was again significantly different (P < 0.04). Ovarian IL-2 and IL-4 mRNA were not expressed in either group. There was no significant difference in the expression of IL-8, IL-13, IFN-gamma and TNF-alpha mRNA in the two groups. These findings suggest that abnormal local expression of certain cytokines may contribute to the development of endometriomata.

Dietary red pepper ingestion increases carbohydrate oxidation at rest and during exercise in runners

The effects of dietary hot red pepper on energy metabolism at rest and during exercise were examined in long distance male runners 18-23 yr of age. A standardized meal was given on the evening prior to the experiment. The subjects had a meal (2720 kJ) with or without 10 g of hot red pepper for breakfast. During rest (2.5 h after meal) and exercise (pedaling for 1 h at 150 W, about 60% VO2max, using cycling ergometry), expired gasses and venous blood were collected. The meal with hot red pepper significantly elevated respiratory quotient and blood lactate levels at rest and during exercise. Oxygen consumption at rest was slightly but nonsignificantly higher in the hot red pepper meal at 30 min after the meal. Plasma epinephrine and norepinephrine levels were significantly higher in those who had only hot red pepper at 30 min after the meal. These results suggest that hot red pepper ingestion stimulates carbohydrate oxidation at rest and during exercise.

Evaluation of the reliability of computed tomographic criteria used in the diagnosis of round atelectasis

The purpose of this controlled study was to determine the diagnostic accuracy of computed tomography (CT) in the diagnosis of round atelectasis (RA). We reviewed two groups of chest CT scans of 22 patients (with 24 masses). Group 1 scans represent 10 patients (12 masses) known to have RA, and Group 2 scans represent 12 patients with "RA look-alike" masses. Scans in both groups were selected for review by two of the authors and later independently reviewed by the other authors, who were blind to the actual diagnosis. Scans were rated for the presence/absence of 18 features ascribed to RA in the literature and assigned a percent probability of RA by each rater. Consensus was achieved for discordant ratings, and the individual percent probabilities were averaged to create a consensus probability. ROC curve analysis of the consensus percent probability showed that diagnostic accuracy significantly exceeded chance [area under curve (AUC) = 0.95, p < 0.001]. Of all the features of RA examined, the presence of converging bronchovascular markings discriminated best between RA and "RA look-alikes" (sensitivity 83%, specificity 92%, likelihood ratio 11). Presence of adjacent pleural thickening and pleural-based location were even more sensitive features of RA (100% each), but lacked specificity (33 and 67%, respectively; likelihood ratios 3 and 1.5, respectively). We conclude that (a) although the diagnostic accuracy of CT for RA was high in this series, radiographic diagnosis is imperfect and that (b) the presence of converging bronchovascular markings was the best discriminator between the two groups, but that no single CT feature permitted perfect discrimination.

Surgical treatment of breast cancer in New South Wales 1991, 1992

BACKGROUND

The purpose of this study was to examine existing data on women diagnosed with breast cancer in New South Wales in 1991 and 1992 and to describe surgical treatments received on an inpatient basis.

METHODS

Analyses were based on the linkage of two databases: the New South Wales Central Cancer Registry and the New South Wales Health Department's Inpatient Statistics Collection. Data were limited to women who were resident and treated in New South Wales. Main analyses were restricted to definitive surgical procedures.

RESULTS

Thirty-six per cent of women treated surgically for breast cancer in 1991 had breast-conserving therapy. This had increased to 39% in 1992. There were substantial geographical variations in the use of breast-conserving therapy in New South Wales which could not be explained by patient characteristics. Age, degree of spread at diagnosis, and area health service/ health region were all found to have an independent association with the probability of having a mastectomy.

CONCLUSIONS

Women with a localized degree of spread living in non-metropolitan areas (Health Regions) were almost twice as likely to have a mastectomy as compared with similar women who were resident in metropolitan areas (Area Health Services). The concentration of radiotherapy services may have contributed to the urban/rural variation in breast-conserving therapy in New South Wales, but it is also likely that some of the variations that were observed may be a reflection of the failure of clinicians to use best current practice.

IL-16 inhibition of CD3-dependent lymphocyte activation and proliferation

We have recently described the cDNA and predicted protein structure of a natural soluble CD4 ligand, IL-16. IL-16 is chemotactic for CD4+ T cells and induces functional IL-2 receptors in CD4+ T cells. The binding of IL-16 to CD4 results in activation of p56(lck), whose adaptor function is essential for the chemotactic response. Subsequently, increases in intracellular Ca2+ and phosphatidylinositol 1,4,5-trisphosphate occur, as does translocation of protein kinase C from cytosol to membrane. Because of the similarities between these signals and functions and those noted for the CD4 ligand HIV-1 gp120, we investigated the potential regulatory effects of IL-16 on CD3/TCR-mediated lymphocyte activation. Preincubation of human T cells with IL-16 up to 24 h before activation with plate-bound anti-CD3 Abs reduced T cell activation by 80%, as monitored by IL-2R expression and [3H]thymidine uptake. If IL-16 was added following anti-CD3 activation, no suppression was noted. The suppressive effects of preincubation with IL-16 were not rescued by the addition of rIL-2 and were not the result of priming for anti-CD3-induced apoptosis. In addition, IL-16 had no effect on surface expression of CD3 or CD4. However, IL-16 did reduce the magnitude of the anti-CD3-induced intracellular Ca2+ increase. These studies indicate that while the interaction of CD4 with its natural ligand, IL-16, results in Ag-independent chemotaxis and IL-2R expression, this pro-inflammatory state is associated with subsequent transient inhibition of responsiveness via the CD3/TCR complex.

IL-16 inhibition of CD3-dependent lymphocyte activation and proliferation

We have recently described the cDNA and predicted protein structure of a natural soluble CD4 ligand, IL-16. IL-16 is chemotactic for CD4+ T cells and induces functional IL-2 receptors in CD4+ T cells. The binding of IL-16 to CD4 results in activation of p56(lck), whose adaptor function is essential for the chemotactic response. Subsequently, increases in intracellular Ca2+ and phosphatidylinositol 1,4,5-trisphosphate occur, as does translocation of protein kinase C from cytosol to membrane. Because of the similarities between these signals and functions and those noted for the CD4 ligand HIV-1 gp120, we investigated the potential regulatory effects of IL-16 on CD3/TCR-mediated lymphocyte activation. Preincubation of human T cells with IL-16 up to 24 h before activation with plate-bound anti-CD3 Abs reduced T cell activation by 80%, as monitored by IL-2R expression and [3H]thymidine uptake. If IL-16 was added following anti-CD3 activation, no suppression was noted. The suppressive effects of preincubation with IL-16 were not rescued by the addition of rIL-2 and were not the result of priming for anti-CD3-induced apoptosis. In addition, IL-16 had no effect on surface expression of CD3 or CD4. However, IL-16 did reduce the magnitude of the anti-CD3-induced intracellular Ca2+ increase. These studies indicate that while the interaction of CD4 with its natural ligand, IL-16, results in Ag-independent chemotaxis and IL-2R expression, this pro-inflammatory state is associated with subsequent transient inhibition of responsiveness via the CD3/TCR complex.

Children's understanding of the meaning and functions of verbal irony

We investigated children's understanding of irony and sensitivity to irony's meanness and humor. In Study 1, 89 participants (5-6-year-olds, 8-9-year-olds, adults) heard ironic and literal criticisms, and literal compliments. Comprehension of irony emerged between 5 and 6 years of age. Ratings of humor increased with age; ratings of meanness did not (showing that all ages perceived irony as more muted than literal criticism). In Study 2, results from 135 participants (6-7-year-olds, 8-9-year-olds, and adults) replicated these findings and revealed the role of form and intonation. Thus, comprehension of irony emerges between 5 and 6 years of age, and sensitivity to the muting function develops prior to sensitivity to the humor function.

Effects of intermittent food restriction and refeeding on energy efficiency and body fat deposition in sedentary and exercised rats

The effects of body weight cycling on energy metabolism and body fat accumulation were examined in sedentary and exercised rats. Ten rats were sacrificed before the experiment to obtain basal data, and then 90 rats were divided into three groups; control (CN), food restricted (FR) and weight cycling (WC). Food intake in rats of the FR group was restricted constantly to 70% of the intake of the CN group. The rats of WC group were subjected to four bouts of weight cycling consisting of 7-days food restriction followed by 7-days refeeding, but were fed the same total amount of dietary energy as that of the FR group throughout the experimental period. The rats of all groups were meal-fed twice a day. Half of the rats in each group were exercised by running on a treadmill (30 min/day) throughout the experimental period. The body weight, abdominal adipose tissue weight, body fat, body protein and energy restoration for the study in both sedentary and exercised groups were greater in the WC group than in the FR group. The resting metabolic rate of the WC group after four bouts of weight cycling was lower than that of the FR group in the sedentary rats, but this difference was not observed in the exercised rats. Also, the thermic effect of food (TEF) in the sedentary rats for 6 h after a meal was significantly less in the WC group as compared to that of the FR group. However, the TEF for the exercised rats was not different between the two groups. The serum insulin level, activities of lipogenic enzymes and lipoprotein lipase in adipose tissue for the sedentary rats of the WC group were higher than those of the FR group, but did not differ in the exercised rats. These results suggest that weight cycling increases body fat deposition and energy efficiency by decreasing energy expenditure, particularly the TEF, and that exercise training can alleviate the effects of weight cycling on the energy metabolism.

Soluble CD23 protein in the peritoneal fluid of patients with endometriosis

Activated B cells are known to produce soluble CD23 protein (sCD23) from their membranes. We recently showed a higher concentration of sCD23 in the serum of patients with endometriosis. As the commonest site of endometriosis is the peritoneal cavity, we sought to evaluate the concentration of sCD23 in the peritoneal fluid of 47 fertile symptomatic women with endometriosis and 35 fertile women without endometriosis. Endometriosis was diagnosed by laparoscopy and confirmed by histopathology. There was a statistically significant difference between the sCD23 concentrations in the endometriosis and control groups (P < 0.05). When endometriosis was defined based on the revised American Fertility Society (AFS) Score, patients with mild (AFS 1 and II) but not severe (AFS III and IV) endometriosis showed a higher and significant difference in the concentration of sCD23 when compared with the controls (P < 0.05). There was no significant correlation between the peritoneal fluid concentration of sCD23 and the phase of the menstrual cycle. We conclude that the concentration of sCD23 is higher in the peritoneal fluid of patients with endometriosis when compared with the controls, suggestive of B cell activation in patients with endometriosis. Furthermore, mild endometriosis is immunologically more active than severe endometriosis as defined by the current classification.

Role of the eosinophil in allergic reactions

The eosinophil may have several functions in health and in the pathogenesis of allergic and other diseases. Some roles of the eosinophil are based on the acute, effector responses of this cell, its capacity to generate biologically active lipid mediators and release its granule contents, including its distinctive cationic proteins. Whilst the effector responses of eosinophils are important for their contribution to the acute pathogenesis of allergic diseases, a fuller understanding of the eosinophil requires evaluation of the role this cell may play at tissue sites, especially submucosal sites, where the cell is normally localized in the absence of disease. Moreover, for the long-lived, tissue-resident eosinophil, definition of the interactions that occur between the eosinophil and other immune cells is germane to understanding the functions of eosinophils both in acute and chronic diseases. Many allergic diseases are characterized by heightened accumulation of eosinophils and are chronic ongoing diseases.

Alterations in CD4 dependence accompany T cell development and differentiation

Several studies have indicated that the necessity for co-receptor engagement during T cell activation depends on the avidity of the TCR-MHC interaction under investigation. Using thymocytes, naive T cells and a long-term T cell line isolated from 2B4 TCR transgenic mice, we have examined the role of the CD4 co-receptor on cells expressing the identical TCR at multiple stages of T cell maturation. When anti-CD4 Fab fragments were used to block CD4-MHC class II interactions, we found decreasing CD4 dependence as T cells matured. As a second approach to examining the role of the CD4 co-receptor, we generated I-Ek mutants defective in CD4 interactions. In the course of this study, we identified a new potential site for CD4 interaction in the beta1 domain of I-Ek. The new beta1 mutation and a mutation in the previously described CD4 binding site in the beta2 domain both interfere with stimulation of 2B4 thymocytes, but not mature T cells. Together these data demonstrate that the role of the CD4 co-receptor depends on the state of maturation of the T cell.

Effect of O-glycosylated mucin on invasion and metastasis of HM7 human colon cancer cells

Mucinous colorectal cancers have a poorer prognosis than colorectal cancers which produce a low amount of mucin, but the exact mechanism is not well understood. The present study was undertaken to elucidate the possible mechanisms of invasion and metastasis of colon cancer cells producing high levels of mucin using mucin glycosylation inhibitor, benzyl-alpha-N-acetylgalactosamine. The binding activity of treated HM7 cells to endothelial leukocyte adhesion molecule (ELAM-1) was significantly decreased and fixed cell binding of MoAb SNH-3 and 19-9 (specific for sialyl Le(x) and sialyl Le(a), respectively) was also significantly decreased. Metalloproteinase activity in conditioned medium and invasion of matrigel-coated porous filters by treated HM7 cells were decreased. However, there was no difference between control and treated HM7 cells in terms of matrix protein binding. These results suggest that O-glycosylated mucin is important in the invasive and metastatic properties of HM7 human colon cancer cells.

Pronase-based assay method for O6-methylguanine-DNA methyltransferase

A new, simple, and rapid assay method for O6-methylguanine-DNA methyltransferase (MGMT) has been developed. When [methyl-3H] DNA radiolabeled with N-[methyl-3H]-N-nitrosourea was incubated together with tissue homogenate, [methyl-3H] group was transferred to the enzyme, forming S-[methyl-3H]cysteine. In contrast to the previous methods which determined the amount of [methyl-3H] group removed from [methyl-3H] DNA, the present method measured the amount of [methyl-3H] transferred to the enzyme. This has been done by hydrolyzing the radiolabeled enzyme with pronase which is a proteolytic enzyme with a broad substrate specificity. On pronase digestion, [methyl-3H]-labeled enzyme becomes soluble in trichloroacetic acid. The method is very simple and rapid, and the only expensive equipment required is a scintillation counter which is a relatively routine piece of equipment at present. More than a dozen samples can be processed within 4-5 h without any difficulty. This new method has been employed in the studies on organ distribution of MGMT of rat and mouse.

Glucocorticoid regulation of androgen binding protein expression in primary Sertoli cell cultures from rats

Glucocorticoids are known to inhibit testicular function, and its receptor is also localized in the Sertoli cells. To evaluate possible role of glucocorticoid in Sertoli cells, the effects of dexamethasone on the expression of androgen binding protein (ABP) have been investigated in primary Sertoli cell cultures. Dexamethasone increased ABP mRNA levels, with maximal stimulation reached at 36 hr. The induction of ABP mRNA was dependent on the low concentration (10(-8) and 10(-7) M) of dexamethasone but gradually reduced in the cells treated with high concentration (10(-6) and 10(-5) M). Dexamethasone-induced ABP mRNA level was no change in the cells after addition of cycloheximide but almost reduced by actinomycin-D pretreatment. Steady-state levels of ABP mRNA gradually increased in the Sertoli cells prepared from 14- and 21-days of age corresponding to rat puberty, and ABP mRNA was induced by dexamethasone. These results suggest that ABP gene is transcriptionally regulated by dexamethasone in primary Sertoli cell cultures.

Effects of red-pepper diet on the energy metabolism in men

We investigated the effects of dietary red pepper on the energy metabolism in male subjects. In the first experiment, after having a standardized dinner on the previous evening, the subjects consumed a breakfast (650 kcal) either with or without 10 g of red pepper. For 150 min after the meal, they took a rest and their expired gas was collected. During the initial 30 min after the meal, the energy expenditure tended to be higher in the red-pepper diet period than in the control diet period. For the remaining 120 min, no difference in the energy expenditure was found between the red-pepper diet period and the control diet period. However the carbohydrate oxidation was significantly higher in the red-pepper diet period than in the control diet period while the lipid oxidation was lower in the red-pepper diet period than in the control diet period for 150 min after the meal. In the second experiment, the subjects consumed a breakfast with 10 g of red pepper after an oral administration of propranolol or a placebo. The propranolol abolished the increase in energy expenditure during the initial 30 min due to the meal containing red pepper. For the remaining 120 min, no difference in energy expenditure was found between the propranolol period and the placebo period. These results suggest than an increase in the energy expenditure after the meal containing red pepper appeared only immediately after the meal ingestion and a red-pepper diet increases the carbohydrate oxidation without increasing total energy expenditure for 150 min after the meal. And an increase in the energy expenditure immediately after the meal containing red pepper is considered to be caused by beta-adrenergic stimulation.

Reduced level of octamer binding transcription factor (Oct-1) is correlated with H2B histone gene repression during differentiation of HL-60 cells by all-trans retinoic acid

To gain insight on the role of transacting factors in the regulatory mechanism of H2B histone gene expression during the differentiation of HL-60 cells by all-trans retinoic acid (retinoic acid), the binding pattern of the nuclear proteins to various elements in the human H2B histone upstream region has been investigated with DNase I footprinting and DNA mobility shift assay. The level of H2B histone mRNA was markedly reduced at 48 hr in retinoic acid-treated HL-60 cells. The H2B histone mRNA was repressed in proportion to the concentration of retinoic acid. In DNase I footprinting analysis, a nuclear factor (octamer binding transcription factor, Oct-1) bound at -42 bp (ATTTGCAT) both before and after retinoic-acid-induced differentiation of HL-60 cells. One DNA-protein complex was formed by DNA mobility shift assay, and the level of Oct-1 decreased during retinoic-acid-induced differentiation. In the cycloheximide-treated HL-60 cells, the level of Oct-1 also reduced. These results suggest that the transcriptional repression of H2B histone gene during retinoic-acid-induced differentiation in HL-60 cells may be mediated by reduced level of Oct-1.

Molecular dynamics of the anti-fluorescein 4-4-20 antigen-binding fragment. 2. Time-resolved fluorescence spectroscopy

Time-resolved fluorescence experiments were performed to investigate the dynamic aspects of the antigen-binding fragment (Fab) of a high-affinity monoclonal antibody (4-4-20) which binds the fluorescent hapten fluorescein. Both the unliganded Fab and a complex of the Fab with a nonfluorescent analog of fluorescein (fluoresceinamine, FLM) were examined. A fluorescence polarization probe [5-[[2-[(iodoacetyl)amino]ethyl]amino]naphthalene-1-sulfonic acid, AEDANS] was covalently attached to the C-terminus of the Fab. Experiments were performed at three different temperatures (10, 25, and 35 degrees C), and phase-modulation data sets were collected for five different molar ratios of FLM to Fab at each temperature. Global analyses were then used to extract values for fluorescence lifetime and rotational correlation time from these data. In the lifetime analysis the best fit was obtained when the emission of AEDANS was described by a Lorentzian distribution of lifetimes (tau = 15.6 ns, distribution width = 3.4 ns, both at 25 degrees C), which suggested that the probe experienced a heterogeneous environment. Anisotropy analyses suggested that two different rotational components were present. The first was attributed to the global motion of the Fab and exhibited a rotational correlation time (theta 1) of ca. 33 ns at 25 degrees C. This component was relatively unaffected by antigen binding. The second rotational component was attributed to the local or segmental motion within the Fab and exhibited a rotational correlation time (theta 2) of 1.1 ns at 25 degrees C. This value increased by more than 50% upon antigen binding, a result which was consistent with molecular dynamics simulations of the same Fab--fluorescein system [Lim & Herron (1995) Biochemistry 34, 6962-6974]. Furthermore, statistical analysis showed that this increase was significant at the 95% confidence level.

Molecular dynamics of the anti-fluorescein 4-4-20 antigen-binding fragment. 1. Computer simulations

Two 174 ps molecular dynamics simulations of the solvated, 4-4-20 antigen-binding fragment (Fab) were performed: one with antigen (fluorescein) in the antigen-combining site and another with it removed. At the beginning of the second simulation, fluorescein was relocated from the antigen-combining site to a point outside the cutoff distance for nonbonded interactions by applying a "pulling force". Initially, the antigen-combining site collapsed when fluorescein was removed but gradually re-formed as the simulation progressed. In addition, several other differences were observed between the two simulations. These included (i) structural rearrangements of key contact residues in the antigen-combining site, (ii) significant differences in the degree of hydration of the antigen-combining site, (iii) a more acute elbow bend angle in the case of the unliganded form, and (iv) less correlated motions of amino acid residues in the unliganded form. These observations suggested that the Fab without fluorescein exhibited a greater degree of segmental flexibility than the Fab with fluorescein. Time-resolved fluorescence experiments were performed in order to validate this prediction, and the results are described in the following paper [Lim et al. (1995) Biochemistry 34, 6975-6984].

Follicle-stimulating hormone transiently induces expression of protooncogene c-myc in primary Sertoli cell cultures of early pubertal and prepubertal rat

The protooncogene c-myc plays an important role in the regulation of cellular proliferation and differentiation. To evaluate the possibility that the protooncogene c-myc plays some roles in follicle-stimulating hormone (FSH)-dependent gene regulation of Sertoli cells, the effects of FSH on the expression of c-myc has been investigated in primary Sertoli cell cultures. FSH was no change to the c-myc mRNA level before 18 h, but transiently increased c-myc mRNA levels, with maximal stimulation reached in 18 h. The induction of c-myc was dependent on the concentration of FSH. Th c-myc mRNA was also increased after treatment with dibutyryl c-AMP and forskolin in primary Sertoli cell cultures. FSH-dependent c-myc mRNA levels were superinduced in cells treated for 3 h with cycloheximide but it was reduced by actinomycin-D pretreatment. Even in the absence of FSH in culture medium c-myc mRNA was clearly detectable in Sertoli cells from 8-day-old rats but hardly detectable in cells from 14 and 28 days of age. FSH stimulated c-myc mRNA expression in the primary Sertoli cells derived from only 8- and 14-day-old rats but had almost no effect in the 28-day-old rats. These results suggest that FSH induces c-myc mRNA levels in the primary Sertoli cells from prepubertal and early pubertal rats, and then transient expression of c-myc may be responsible for some roles in the regulation of FSH-dependent genes in Sertoli cells.

Inhibition of rabbit aortic smooth muscle cell proliferation by selective inhibitors of protein kinase C

1. We studied the effect of two structurally-related, selective inhibitors of protein kinase C, Ro 31-8220 and Ro 31-7549, on the reinitiation of proliferation in quiescent first passage rabbit aortic smooth muscle cells in response to (a) the direct activator of protein kinase C, phorbol dibutyrate (PDBu), (b) platelet-derived growth factor (PDGF), (c) a combination of PDGF and 5-hydroxytryptamine (5-HT) or (d) serum. 2. Ro 31-8220 and Ro 31-7549 concentration-dependently inhibited proliferation in response to each mitogen. The inhibitory potency (IC50) of Ro 31-8220 and Ro 31-7549, respectively, was similar against proliferation induced by PDBu (0.55 and 1.1 microM), PDGF (0.6 and 0.9 microM), PDGF and 5-HT (0.68 and 1.1 microM), although slightly less against serum (1.7 and 5 microM). The effects of the protein kinase C inhibitors on proliferation could not be ascribed to cytotoxicity. Neither Ro 31-8220 nor Ro 31-7549 (0.3-3 microM) inhibited PDGF receptor tyrosine phosphorylation. 3. The results show that Ro 31-8220 and Ro 31-7549 are potent inhibitors of smooth muscle cell proliferation in response to a direct activator of protein kinase C, the defined growth factors, PDGF and 5-HT, and the complex mixture of mitogens in serum. Protein kinase C activation thus appears to be an important growth transducing mechanism for each of these agents.

Promotion of microtubule assembly in vitro by a novel 35-kDa protein purified from human term placenta

Microtubule assembly promoting-protein (taxol-like protein, TALP) was purified by combination of high salt extraction, phosphocellulose chromatography and hydroxyapatite chromatography from human term placenta. Molecular weight of purified protein was identified as 35kDa on SDS-polyacrylamide gel electrophoresis. In vitro, TALP promoted microtubule assembly in dose-dependent manner in spite of the absence of GTP. Both TALP (0.5 microM) and taxol (10 microM) gave hyperbolic kinetics and shortened the lag time for microtubule polymerization. TALP-stabilized microtubules were resistant to depolymerization by cold (4 degrees C) and CaCl2 (4 mM) like taxol-stabilized microtubules. TALP showed its direct binding on the microtubule in cosedimentation assay. These results suggest that the action mechanism of TALP on the microtubule assembly is similar to taxol in vitro and the binding site of TALP is available on the intact microtubule.

Acylshikonin analogues: synthesis and inhibition of DNA topoisomerase-I

Compounds bearing an acyl group of a various size at 1'-OH of shikonin were synthesized as acyl analogues of shikonin, which was isolated from the root of Lithospermum erythrorhizon, and evaluated for inhibitory effect on topoisomerase-I activity. A selective acylation at 1'-OH of shikonin in the presence of dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine gave rise to a good yield of corresponding acylshikonin derivatives. In general, analogues with an acyl group of shorter chain lengths (C2-C6) exerted a stronger inhibitory action than those with longer chain lengths (C7-C20). While the halogen substitution at C-2 of the acetyl moiety failed to increase the inhibitory potency, the placement of double bonds in the acyl group (C5-C7) augmented the potency remarkably. Of the 32 derivatives evaluated, 15 compounds exhibited a higher inhibitory effect than shikonin. Noteworthy, the inhibitory potency of acetylshikonin, propanoylshikonin, and 4-pentenoylshikonin was approximately 4-fold greater than that of camptothecin. All these data suggest that the size of acyl moiety is important for the enhancement of potency, and the presence of olefinic double bonds is also beneficial.

Osteoarthritis of the scapho-trapezial joint

In a cohort of 199 patients with OA we studied the prevalence of radiographic scapho-trapezial joint osteoarthritis (STJ OA) and its clinical features. The prevalence of STJ OA was 38%. Lone STJ OA occurs but is uncommon (11%). In contrast, STJ OA in combination with first carpo-metacarpal joint OA was found in 27%. There appears to be an age-related progression from those without disease to lone disease to combined disease. The most frequent radiological features seen were joint space narrowing, subchondral sclerosis and osteophytes. There was a weak correlation between STJ OA and palpable swelling at the thumb base (phi = 0.231, P = 0.01) but no association was found between STJ OA and tenderness at the thumb base.

Three-dimensional structure of Schistosoma japonicum glutathione S-transferase fused with a six-amino acid conserved neutralizing epitope of gp41 from HIV

The 3-dimensional crystal structure of glutathione S-transferase (GST) of Schistosoma japonicum (Sj) fused with a conserved neutralizing epitope on gp41 (glycoprotein, 41 kDa) of human immunodeficiency virus type 1 (HIV-1) (Muster T et al., 1993, J Virol 67:6642-6647) was determined at 2.5 A resolution. The structure of the 3-3 isozyme rat GST of the mu gene class (Ji X, Zhang P, Armstrong RN, Gilliland GL, 1992, Biochemistry 31:10169-10184) was used as a molecular replacement model. The structure consists of a 4-stranded beta-sheet and 3 alpha-helices in domain 1 and 5 alpha-helices in domain 2. The space group of the Sj GST crystal is P4(3)2(1)2, with unit cell dimensions of a = b = 94.7 A, and c = 58.1 A. The crystal has 1 GST monomer per asymmetric unit, and 2 monomers that form an active dimer are related by crystallographic 2-fold symmetry. In the binding site, the ordered structure of reduced glutathione is observed. The gp41 peptide (Glu-Leu-Asp-Lys-Trp-Ala) fused to the C-terminus of Sj GST forms a loop stabilized by symmetry-related GSTs. The Sj GST structure is compared with previously determined GST structures of mammalian gene classes mu, alpha, and pi. Conserved amino acid residues among the 4 GSTs that are important for hydrophobic and hydrophilic interactions for dimer association and glutathione binding are discussed.

Testosterone regulation of proto-oncogene c-myc expression in primary Sertoli cell cultures from prepubertal rats

The expression of c-myc has been associated with cell proliferation through changes of nuclear function. To evaluate the possibility that the proto-oncogene c-myc plays a role in testosterone-dependent gene regulation, the effects of testosterone on the expression of c-myc have been investigated in primary Sertoli cell cultures. Testosterone increased c-myc mRNA levels, with maximal stimulation reached in 16 hours. The induction of c-myc mRNA was dependent on the concentration of testosterone. Testosterone-induced c-myc mRNA levels were also increased in cells after addition of cycloheximide but reduced by actinomycin-D pretreatment. Even in the absence of hormone in culture medium, c-myc mRNA was clearly detectable in Sertoli cells from 8-day-old rats but hardly detectable in cells from 14 and 28 days of age. Testosterone stimulated c-myc mRNA expression in the Sertoli cells from only 8-/and 14-day-old rats. These results suggest that testosterone induces c-myc mRNA levels in the primary Sertoli cells from prepubertal rats, and then transient expression of c-myc may be responsible for some of the regulatory roles of testosterone-dependent genes in the Sertoli cells. The biological significance of testosterone-dependent c-myc induction is not known.

Acute inflammatory polyarthritis in association with tamoxifen

The antioestrogen drug tamoxifen is widely used to treat breast carcinoma. We report three cases in which its use was temporally related to the development of an acute inflammatory polyarthritis resembling RA; a side-effect not previously reported. Possible mechanisms for such an effect are discussed.